Drying process and apparatus.



0. P. BOSSERT. DRYING PROCESS AND APPARATUS APPLICATION FILED APRA,1910. 1,046,254 Patented Dec.3, 1912.

3 SHEETS-SHEET l.

Inven or Charles P 2"? W1 messes DSSETI A carnage G. P. BOSSERT.

DRYING PROCESS AND APPARATUS.

APPLIGATION I'ILBD APR.4, 1910.

1,046,254, Patented Dec. 3, 1912.

3 SHEETSSHEET 2. F 4. a ,4

W Ch l e Euss'fir W Ell-11E 5 C. P. BOSSERT.

DRYING PROCESS AND APPARATUS.

APPLICATION FILED MBA, 1910.

Patented Dec. 3, 1912.

3 SHEETS-SHEET 3.

a/ a I 73 a m I3 5 r m 1:" I I a I l I I I I l I I I I l I '1 I InvanInrW1 11855515 W5 P. 112 5514 UNITED STATES PATENT OFFIQE-.

CHARLES P. BOSSERT, OF-MILWAO'KEE, WISCONSIN, ASSIGNORTO PFISTER & VOGELLEATHER 00., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

DRYING PROCESS AND APPARATUS.

Specification of Letters Patent.

Patented Dec. 3, 1912.-

T at, whom it may concern:

Be it known that I, CHARLES P. Bossnn'r, a

citizen of the United States, residing at new and Improved DryingProcess and Apparatus, of which the following is a full, clear, concise,and exact description, reference being had to the accompanying drawings,forming a part OfthlS specification.

My invention relates to drying processes and apparatus therefor.

Although the improvements which I propose may be used, as will be seen,in a great many instances and in connection with various industries, Icontemplate the use thereof particularly in tanneries, and willtherefore. describe my invention with this specific embodiment in mindso as to facilitate the explanation thereof.

It will appear that the process and apparatus of my invention arepeculiarly adapted to the drying of fibrous materials which may becomemore or less wet or, in fact, saturated, and it is clear, in view ofthis fact, that .my invention may be advantageously employed inconnection with tanning proc esses. In such processes hides are broughtinto a thoroughly saturated state during the tanning step in which theyare subjected to the action of the various tanning solutions and, beforethe further dressing and currying processes, it is necessary that theybe dried thoroughly.

From the following description of the process and the operation andconstruction of the apparatus of my invention in connection with its usein the tanning art, the adaptability thereof to many other similar useswill become manifest.

- In the known art it has been customary, in tanning establishments, tohang the wet hides in a room or chamber provided for that purpose, andto heat and ventilatethat room or chamber to a proper'extent so that thedrying (if the hides may ensue. These rooms or chambers are heated bysteam coils or in some other suitable manner, and the hides are hungabout the room as best they can be to save space. Considering the partthis drying step plays in the complete tanning process, it will beunderstood why the most practical plan under this prior art arrangementwas to transfer a certain lot of hides after they had been removed fromthe tanning pits or'vats to this drying chamber and to allow them toremain in this chamber or room, under the influence of the heat and suchdraft as could be had, until they were thoroughly dried. The hides werethen removed and'the room or chamber was ready for the reception ofanother lot. In this practice it was found necessary to allow the hidesto rest under those conditions for a period amounting, on the average,to about eighteen hours, such a considerable length of time beingrequired because of the fact that the hides could not be heated evenlynor disposed in a draft evenly, the moisture from some of the hidesbeing transferred to others, depending upon the respective temperatures,and vice versa, with a gradual loss until all the moisture had becomeevaporated. v

It is the object of my invention to provide means whereby the hides, orfor that matter, other articles, can be dried in a much which isconsistent with the convenient and.

expeditious handling and manipulation of the hides.

It is the further object of my invention to provide a process andapparatus in which regulatioumay be had to a degree and in whicheffective control may be had at all times. And it is the further objectof my invention to .carry out the proposed process by means of anapparatus of such simple design and construction that its cost would notoverbalance the practical advantages to be gained thereby.

The process of my invention includes the provision of a well-defineddraft, preferably heated, entails the movement of the articles to bedried in such a draft against the direction of the draft, and theheatingof the hides before they are introduced into the draft. Theapparatus of my invention provides for carrying out the process as,

thus outlined and for doing so, more specifically, in a definite manner.The apparatus which I propose is mainly and essentiallyin the form of atunnel through which the hides or other articles to be dried arecarried. The wet hides are introduced at one end and are ejected at theother, and practice and experiment have proven that hides may bethoroughly dried in the proposed sectional view of the manner by timingthe trip through the tunnel to one hour and a half quite in contrast tothe eighteen hours required by the means of the prior art, ashereinbefore pointed out. The apparatus which I propose provides foraffecting the hides uniformly and provides for their physicalmanipulation in an eflicient and convenient manner. Once introduced intothetunnel, the hides need no further attention, and the tunnel itselfneeds no further attention than to regulate the temperature.

The improvements I propose are carried out by an embodiment in theapparatus illustrated in the accompanying drawings, in which Figure 1 isa side elevational view thereof, showing its relation to the parts ofthe building in which it is set up, parts being broken awayso that itsproportionate length may be confined to the sheet; Fig. 2 is a plan viewthereof; Fig. 3 is a partial crosssectional view taken on the planeindicated by the line 3-3 of Fig. 2 and looking in the directionindicated by the arrows, this part being near the ejecting end of thetunnel; Fig. 4 is a partial sectional View taken on the plane indicatedby the line 44 of Fig. 1 and looking in the direction indicated by thearrows, this part being at the entrance end of the tunnel; Fig. 5 is apart of the apparatus just below the partshown in Fig. 3, beingtherefore a section taken on the plane indicated by the line 33 of Fig.1; Fig. 6 is an end View of the tunnel, showing the entrance end,'andFigs. 7, 8 and 9 are detail views which will be later referred to andwhich illustrate parts of the carrying mechanism. Like referencenumerals are applied to the same parts throughout the various figures.

The tunnel is shown at 10, the middle part thereof extending between twobox portions 11 and 12, which are preferably mounted upon the floor 13,the part 10 being therefore quite in tunnel comprising these three partsis preferablyconstructed by means of a stout mechanically resistantframework comprising the uprights 14, 14 and suitable horizontal bars,the main horizontal supporting member being in the form of a .U-bar 15disposed on eachside of the structure. The U -bars 15 extend beyond theentrance box 11 to a considerable extent, for a purpose hereinafterfully polnted out.

The frame-work thus described is preferably provided with an expandedmetal or wire screen wall so as to form a foundation for the plasterwalls, as shown in the drawings. Plaster walls are preferable since theydo not radiate the heat to any substantial degree, and therefore serveto confine it to the most useful the form of a bridge. The" region. Itis the part 10 of the tunnel that primarily carries the current or draftof air, and this part is therefore made of such height as toaccommodate, with a reasonable degree of fitness, a doubled hide, sothat when the tunnel is full the draft will be intercepted as much aspossible and will find little or no path of low resistance. It is ofcourse clear that a number of rows of hides can be sent through thetunnel, and that the tunnel can be adapted therefor without departingfrom'the spirit and scope of this invention.

The carrying mechanism is in the form of a pair of traveling chains, oneon each side of the tunnel, which operate upon sprockets which aredriven in some suitable manner. The sprockets at the exit end areindicated at 16, 16, and those at the entrance end are indicated at 17,17. Those at one end may be permanently mounted, While those at theother end are preferably adjustably mounted. In the present embodimentthe sprockets 16, 16 are shown as mounted upon the stationarily confinedshaft 18, while the sprockets 17, 17 are shown as mounted upon the shaft19, which is journaled in sliding boxes 20, 20 mounted in elongatedframes 21, 21 secured in some suitable manner to the frame-work. Thesliding boxes 20, 20 each are provided with an adjusting screw22 whichhas threaded engagement with a lug 23 on the frame 21, and it is clearthat manipulation of the hand-Wheel 24 will opcrate to tighten or loosenthe corresponding chain 25 which operates over the respective sprockets.The chains 25, 25 are provided with suitable, uniform, and laterallyregistering intervals with special links 26, 26, (Figs. 7 and 8) each ofwhich is provided with a lug 27 to which is secured, by means of rivets28, 28, a T-bar 29, these T-bars extending between registering links, asis evident from the drawings. Placed in respective parallel proximity tothe two sides of each sprocket chain are the angle irons 30 and 31, theupper iron 30 being above the upper run of the sprocket chain, and thelower angle 31 being below the lower run of the sprocket chain. Thepurposes of these angle irons will be presently apparent. Also securedto the lug'27 of each of the speclal links 26 of the sprocket chain isthe lug 32, of the truck frame 33 which carries, in longitudinalalinement, the rollers 34, 34. These rollers are adapted to ride uponthe angle irons 30 and 31 so that the latter act as rails and, as willbe clear, supporting rails. It is to be noted that only one side of thesprocket chain passes through thetunnel, the other side passing .outover the tunnel; the object of this arrangement will be pointed outlater -when the operation of the device is described. As best shown inFig. 4, the hides are adapted to be hung on cross-bars exof the flangesof the T-bars is provided with a plurality of preferably regularlyspacedstruck-up portions 35, 35, which act as abutments for properlyspacing the cross-bars 36, 36, which are removable and preferably ofwood so as to be light and so, conveniently handled. In hanging thehides on the carrying means, the hide is first placed over such across-bar or stick 36 and the stick is then hung between adjacent'T barsagainst corresponding abutments 35, 35, in Fig. 9 the bars beingpreferably put in place from the right.

As will be later pointed .out, the draft enters the tunnel from the endshown in Fig. 3, and it is therefore apparent that there must be somespecial construction for that end in order that the sprocket chain maypass out of the tunnel, since that arrangement is desirable, as will bepointed out. Referring to Fig. 3, it will be seen that the tunnel atthis point is 'made of slightly greater height than the greater port-ionof the part 10, as indicated at 37. The'to-p wall which is thusauxiliary is above the rail 30, which I may refer to as the return rail,and the opening which thus results is closed partly by the verticalportion 38 and mainly by a series of gates 39, 39 which are pivoted at40, 40 to the frame-work, which extend across the tunnel and rest uponthe rails 30, 30, and which are inclined in the direction in which theupper run of the chain moves, so that they may automatically respondand. allow the trucks and T-bars to pass out of the auxiliary portionwithout interference. A number of such gates being provided, and beingproperly spaced, it is clear that when one of the gates is open one ormore of the others is closed, and the draft therefore finds no outlet atthis point. I

Beyond the exit end of the tunnel a chamber 41 is disposed, this chamberbeing in part a heating box and also providing means for conducting theair, freely admitted to said heating box, to arotary blower indicated at42. Heating coils are shown at 43 and, as shown, the chamber or casing41 is open at the end so that the air may be admitted thereto freely andmay pass among.

the heating coils, in which steam may be circulated, this action beingencouraged by the operation of the 11142 which, so far as the entranceof air to the heating box is concerned, acts as a suction element. fan42 is connected at its outlet end with a pipe 44 which leads to theopening 45 in the end of the wall of the tunnel at its exit end (Fig.3). The blower 42 is provided with a pulley 46 which is connected withthe pulley 47 on the jack shaft 48 by means The of a belt 49, this jackshaft being opera- P tively connected with a rotating element 50 of asource of power by means of the pulley 51 andthe belt 52. In order thatthe carrying mechanism may also be operated from the jack shaft acounter-shaft 53 is provided upon which tight and loose pulleys arearranged, the jack-shaft being permanently connected with thecounter-shaft 53 by means of the belt 54, and the countershaft beingconnected with a pulley 55, mounted on the tunnel frame-work, by meansof a belt 56 permanently connected with a loose element on thecounter-shaft 53 and arranged to be brought in or out of service bymeans of the shifting fork 57 which is operated by means of a wheel 58connected with a pulley 5.9 by means of a cord 60, this pulley 59 beingoperated in one direction or the other by 'meanso-f the operating cords61, 61 which carry the weights 62, 62 in an obvious manner. The pulley55 is carried upon a shaft 63 which also carries a pinion 64' which, inturn, meshes with a gear 65 on the same shaft 18 with the sprockets 16.It is clear that the carrying arrangement may be brought into and out ofservice conveniently by a person at the entrance end ofthe tunnel bymeans of the arrangement thus described, it being understood, however,that this is shown merely as an example and is not to be regarded as themeasure of the scope of any phase of mv invention.

About midway between the ends of the tunnel and preferably toward theentrance end, an outlet 66 is provided, this outlet being in the natureof a tap from the tunnel so that. the draft created by the blower 42 andpassing through-the tunnel will pass out through this outlet and notthrough the entrance end of the tunnel. The outlet flue isin the form ofacanopy 67, which is supplemented by a pipe 68 passing upwardlypreferably through the roof and to the open air where it is rovided withsuitable hoods 69, '69, for obvious purposes. The canopy 67 is providedwith the pivoted gates 70, 70 constructed quite in accordance with thedescription of the gates 39, 39, so as to accommodate the return sidesof the sprocket' chains without interfering with the air current arranement. The pipe 68 is provided with a fan 71 which is operated in somesuitable -manner, for instance by means of gearing and shafting 7 2, andtends tocreate a draft upward so as to assist the fan 42 in creating andmaintaining the particu-.

before they are introduced into the draft.

The steam coils preferably extend the entire length of the box so thatsufiicient heat may be had to secure the desired result, as will bepointed out when the operation of the arrangement is described.

It is clear from Fig. 3 that when a T- bar reaches the sprockets 16, 16the main portion thereof will extend approximately radially from thecenter of the sprocket, this action resulting in the lengthening of thedistance between the rear flange of the T-bar and the forward flange ofthe T-bar following it, to such an extent that the crossbars or stickscan no longer be held thereby and they are dropped into the box 12,together with all the hides carried thereby. The bottom of the box 12 isopen, as indicated at 73, but this opening is controlled by a slidingdoor 74 supported upon crossbeams 75, 75 carried'upon rollers 76, 76which ride, upon rails 77, 77. The opening 73 is preferably made in thefloor and, below the floor, is surrounded by a sash 78, the lower faceof which is oblique to the rails 77. The door 74 is also mounted so asto be oblique, or has a surface oblique to a similar degree, so that awedge action is produced when the door is jammed shut, that is, when thedoor is rolled to the right as far as it will go. In order that thejoint between the door and the sash may be airtight, so far. aspossible, the sash or the door, or both, may be provided with acompressible washer member 79 of suitable material, for instance, a hidewithout the hair removed. This has proved a very eflicient joint, andthe entire arrangement well fulfils the broad object of normallyconfining the draft, to the tunnel proper. The door carries a rack 80which meshes wit-h a pin- 1011 81 operating on a relatively stationaryshaft 82, this shaft also carrying the operating sprocket or sheave 83which, in turn, carries the operating chain 84, adapted to be manuallyoperated, as is well known in other devices. Thus when a lot of hidesfalls from the carrying mechanism they fall down into the box '12 andupon the door 74, when warning may be given to the floor below that thedoor may be shifted to remove all the hides and sticks which are carriedthereby. 4

In order that access may be had to. the various interiors for thepurposes of adjustment, repair and regulation, manholes 85 may beprovided. In order that regulation of temperature may be. convenientlyhad, sight-holes 86, 86 may be provided in the tunnel, behind whichthermometers may be placed, a glass cover being-provided so that theheat may be confined.

The process of my invention, and the manner in which it is carried outby the apparatus which I propose will now bedescribed. I

The blower 42, together with the auxiliary fan 71, maintains a constantcurrent or draft fro-m the exit end of the tunnel to the outlet 66, thisdraft or currentbeingthoroughly heated by meansof the heatingarrangement. 43, 43. By this arrangement the hottest and driest parts ofthe draft are at the exit end, the temperature being probably and notonly is the heating proposed by the rocess of my invention advantageousfor t is purpose, but it alsobrings the hides to substantially thetemperature of the draft before it is introduced into the same.

In carrying out my invention an operator is stationed at the entranceend of the tunnel, where he may operate the shifting mechanism forstarting or stopping the carrying means. The carrying means is operatedintermittently, in fact it is stationary most of the time. It isstationary while a lot of hides are put in place. When the parts are inthe position shown in Fig. 4 the two T- bars farthest to the left in thefigure are ready for the reception of the cross sticks carrying thehides. It is to be understood, of course, that the hides are hung onlyon the lower runs of the sprocket chains, since that part only passesthrough the tunnel.

Thus as the T-bars come upon the lower steps in the tanning processmaybe carried out. He, places each hide over a stick and then places thestick between the two T-bars between which he is working. When the rowis completed he operates the shifting" cords 61, 61 to start thecarrying mechanism, to move the hides farther on in the tunnel, and tobring the next T-bar down into place upon the lower rails 31, 31, sothatanother lot of hides may be put into posltion. It is clear that,continuing this operation, the hides are gradually assed over the heatcoils in the box 11 an that they are heated to a considerable degreebefore they reach the draft which, so far as the tunnel is concerned,ends at the outlet 66.

As is well known in the art, moisture does not deposit much on a warmhide, while it does deposit upon a cold hide very rapidly.

rate at which moisture'deposits. It-is further well known that amoist'3hide offa higher temperature will impartits moisture,

or a-part' thereof, to a colder hide and, 'co nsistently, a hide ofa'certai ntem rature being thoroughlywet will impartnts moisture toanother hide of the same'tempera-f ture if it is not so wet. The imortance of systematic physical man' 'ulatlon or the hidesin accordancewith the draft and the temperature is thus at once realized, for, in thedrying chambers or roomsof the prior art, it is clear that moisturewould be im-- parted from one to the other of the hides, and that thetemperatures might affect them to no distinct advantage and so delaytheentire process. The depositing of moisture upon a hide means thatmoisture is depos ited upon an oilwhich, itself, is over moisture, andthis intermingling of oil} and water gradually delays any kind ofdrying. Thus the primary heating of the hides is doubly important, forif it had no effect whatever in securing primary evaporation it would.be effective in bringing the hidespfito .such

temperature that theywould not take on any of the moisture given oflj.,by those that preceded them.; Thus if the 'hides'are thoroughly warmbefore they freacht-he draft, the moisture 'held by. the air; will notdeposit upon the hides, but will pass" out .of the flue with the air,and ohly'the primary moisture contained by the hideslneedbe evaporatedby thedraft into which they are to be introduced. -The movement of thehides-in a di-' rection opposite to the direct-ionfpf the heated aircurrent-.isialso -important, for LOl only do the hides become more.dry-as they move toward. the" exit end of the tunnel, but the air whichafi'ectsthem is also more dry.

Consistently; they need not be brought up to such a'greati..-temperature near the end of the draft, for there thetemperature of the draft ,is'considerably lessvthan at the exit end; Asthehides pass toward the exit end they are gradually subjected togreater heat and 'idrier air. until finally they' may be ejectedina-thoroughlydry condition. Only one sideof the; carrier chain being:led

Y through the tunnel, is'clear that the "hides willcover thejcrossj-s'ection as thoroughly as.

practicable,and tlierelis no ath of low. re?

sistance, above ;the1 hides w iclr the draft might: otherwiseAsthe'fl-hides enterthe.tunnelandfgradually"approach the endofthefidraft they become heated more and a more y -the draft,". tli

mg into I and the tem rature slightly higher." During its 'trave as faras the r ,gs areg of approximately the t'emperatureofthat end of thedraft. Com the draft the; air somewhat moist aft it'is likely thatconsiderable {of themoisture has been 11y, just before they reachevaporated from the hides, but I do not rely upon this feature for theproper operation 0 my process. Having brought the hides to the desiredtemperature before they are introduced into the drying draft, themoisture contained by the air of the draft, particularly at'the endthereof, will not tend to settle on the hides, but will, in fact, tendto take hp more and so relieve the newly entering hides. The hides thengradually approach the exit end and, simultaneously, ap-

proach the highertemperature anddrier a1r to secure the desired result,as hereinbefore pointed out. y 1

It is'clear that while a large number, of hides are physically handledat the same time they are also simultaneously acted upon in accordancewith the process of my 'invention. The hides are constantly being introduced and accordingly being taken out of the tunnel, so'that there is acomplete cycle, the greater portion of which involves the passage of thehides through the tunnel to secure the proper drying, as set forth.

I claim as new and desire to secure by Letters Patent:

1. A drying process consisting in constantly maintaining a forced heateddraft from the atmosphere through an inclosure and back to theatmosphere, primarily and independently dry-heating wet articles, thenintroducing the heated wet articles into said draft by graduallyshifting them from the primary heating zone to the zone of said draft,and then passing said articles through said draft.

'2. A drying process consisting in constantly maintaining a forcedheated draft from the atmosphere through an inclosure and back to theatmosphere, primarily and independently dry-heating wet articles, thenintroducing the heated wet articles into said draft by graduallyshifting them from the primary heating zone to the zone of saiddraft,=jand then assing said articles through said draft in a directionopposite to that of the draft. '3. A drying rocess consisting inconstantly. maintaimng a forced heated draft from the atmosphere throughan inclosure and back to the atmosphere; primarily and independentlydry-heating wet articles to a temperature approximate equal to that ofthe colder end of said draft, then introduc--- ing the heated wetarticles into said draft by gradually shifting them from the primaryheating zone to the colder end of said draft, and then passing saidarticles through said draft.

.4. A drying process consisting in constantly maintaimn a defined draftheated at .the'beginning. ereof and passed from the atmosphere throughan inclosure and back to the atmosphere, primarily and independentlyheating wet articles to a temperature approximately equal to that of theend of the draft, then introducing the heatedwet articles into saiddraft by gradually shifting them from the primary heating zone to thezone of said draft, and then passing said articles through said draft.

5."A drying apparatus comprising a permanently open tunnel having anintermediate outlet to the atmosphere, heating means confined to one endof said tunnel, heating means independent of said first-named heatingmeans confined to the other end of said tunnel, a blower associated withsaid lastnamed heating means and arrangedto induce a draft toward saidintermediate outlet, and a conveyer extending through said 7 tunnel.

' means confined to 'one end'of said tunnel,

heating means independent of said firstnamed heating means confined tothe other end of said tunnel, a blower associated with said last-namedheating means and'arranged to induce a draft toward said intermediateoutlet a' conveyer extending through said tunne a rotor, and means fordriving said blower and said conveyer from said rotor. 8. A dryingapparatus comprising a tun-' nel having an intermediate outlet,conveying mechanism therein, heatingmeans at the entry end thereof, afloor outlet at the exit end thereof, an external box, a heater in saidbox, a blower therein, and connection between the blower end of's'aidbox' and the top of the tunnel at the exit end, the

box being open to the tween the carriers on one side and .those ontheother.

10. A drying apparatus comprising a permanently opentunnel having anintermediate outlet to the atmosphere, a conveyer extendin into saidtunnel from the entry end neafiyto the opposite end, an outlet door inthe floor at the end of said conveyer, heating means confined to saidopposite end of said tunnel, a blower associated with said heatingmeans, said blower inducing a heated draft from said heating means tosaid intermediate outlet, and heating means independent of. saidfirst-named heating means confined to the entry end of the tunnel, thezone between that at said last-named heat-ing means and saidintermediate outlet being a graded zone subject to the induced heat fromboth means.

11. In a drying apparatus, a tunnel, carryin means in the form 'of abelt, one run 0 y of which passes through said tunnel, supporting meanscarried by said belt, and a plurality of serially disposed automaticallyoperated gates providing for the exit of said supporting means.

12. In a drying apparatus, a tunnel, means for maintaining a draft insaid tunnel, means for carrying a plurality of transversely extendingT-beams through said tunnel, the flanges of said 'T-beams havingstruck-up portions to form abutments against which cross sticks may belaid.

, In witness whereof, I hereunto subscribe my name this 30th day ofMarch, A. D. 1910.

CHARLES P. BOSSERT. Witnesses:

' G. MAIER, l R. S. BOEMER.

